Potassium bromate replacer composition

ABSTRACT

A method of preparing potassium bromate replacer comprising an ascorbic acid composition in an effective amount to replace an oxidizing agent of potassium bromate is disclosed. The potassium bromate replacer essentially comprises ascorbic acid, food acid, and/or phosphate. It is a slow acting oxidant that is functional throughout the entire manufacturing process. It is also an effective oxidant that produces properly oxidized dough needed in the production of high quality, yeast-leavened products using various methods of the breadmaking process.

This a continuation of application Ser. No. 08/147,995, filed Nov. 05,1993.

BACKGROUND

1. Field of the Invention.

The present invention relates to oxidizing agent replacers and to theirmethods of preparation. More specifically, the present invention relatesto a potassium bromate replacer comprising an ascorbic acid compositionthat replaces an oxidizing agent of potassium bromate and to methods fortheir preparation.

2. Background of the Invention.

Oxidizing agents provide strengthening of dough during the manufacturingprocess of yeast-leavened products. As a result, oxidizing agents areused to provide greater loaf volume, improve internal characteristicssuch as grain and texture, and enhance symmetry and keeping quality ofyeast-leavened products.

The manufacturing process of yeast-leavened products benefits from theeffect of a dough oxidizing agent in the mixing, proofing, baking,and/or other stages of the process. Oxidizing agents are similar incontributing to the strengthening of dough but have different rates ofreaction. For example, oxidizing agents such as potassium iodate,azodicarbonamide, and ascorbic acid are fast acting and mainlyfunctional during mixing and to a slight extent during proofing, but arelargely dissipated during the later stages of proofing and the earlystages of baking. Potassium bromate is a slow acting oxidant and mainlyfunctional during the later stages of proofing and the early stages ofbaking. Thus, the baker can combine fast and slow acting oxidants toprovide adequate strengthening of dough throughout the entiremanufacturing process. However, these combined oxidants havedisadvantages because they become chemical additives, thereby requiringfull labelling by complete chemical name. The present invention hasadvantages of using ascorbic acid as the only oxidizing agent andproviding adequate strengthening of dough throughout the entiremanufacturing process.

Food and Drug Administration (FDA) regulations also limit the levels ofall oxidizing agents permitted for use in yeast-leavened products,except ascorbic acid. The bromates and iodates should not exceed 75 ppm(parts per million) by weight of flour used in the formula.Azodicarbonamide may be used in addition to bromates and iodates at alevel of not more than 45 ppm. Currently, no limitation for ascorbicacid exists except "safe and suitable", although previously this wasspecified as 200 ppm maximum. Thus, the present invention isparticularly useful that it provides natural ascorbic acid as the onlyoxidizing agent in dough that is effective and functional throughout theentire manufacturing process.

In order to allow ascorbic acid to be functional during the early stageof baking, ascorbic acid can be encapsulated with high-melting point fatthat will not melt until the baking stage has reached the adequatetemperature in the oven. The ascorbic acid can also be coated with 2 to3% edible cellulose to obtain longer shelf life during storage thanuncoated ascorbic acid. Both encapsulated and coated ascorbic acids havedisadvantages as these are not functional during the later stages ofproofing. The present invention has the advantage of using unmodifiedascorbic acid that is functional throughout the entire manufacturingprocess. However, coated ascorbic acid can also be used in accordancewith the teachings of the present invention to increase the shelf lifeof ascorbic acid.

Due to its natural status, the only oxidizing agent approved in manyparts of the world is ascorbic acid. Potassium bromate is a majoroxidant used in the United States, although its use has been banned inthe State of California.

Oxidizing agents that do not contain potassium bromate are now availableto the baker in powdered and tablet forms. In addition to ascorbic acidand/or azodicarbonamide, potassium bromate replacers contain calciumperoxide, L-cystein, fungal enzymes, and other edible excipients. Asmore bakers are replacing potassium bromate with ascorbic acid only orpotassium bromate replacers, they are discovering that product qualityhas suffered. Continuously mixed and frozen doughs seem to have sufferedthe most. Thus, a need exists in the baking industry for an effectivepotassiu bromate replacer to produce high quality, yeast-leavenedproducts. As a result, much effort has been directed to provide anoxidizing agent that replaces potassium bromate.

To function as a potassium bromate replacer, many known compositionsthat are currently in use include ascorbic acid as the only oxidizingagent or combine ascorbic acid with other oxidizing agents and/oringredients. However, these potassium bromate replacers havedisadvantages because these have a fast or intermediate reaction rateand thus, they are not functional during the later stages of proofing orthe early stages of baking.

Given the state of the existing potassium bromate replacers, there is acontinuing need for a new and effective potassium bromate replacer usingascorbic acid as the only oxidizing agent that is functional throughoutthe entire manufacturing process of yeast-leavened products.Accordingly, it is an object of the present invention to provide aneffective potassium bromate replacer.

It is another object of the present invention to provide an ascorbicacid composition suitable in the preparation of the potassium bromatereplacer and methods for their preparation.

It is a further object of the present invention to provide the ascorbicacid composition that acts as a slow acting oxidant that is functionalthroughout the entire manufacturing process.

It is a further object of the present invention to provide properlyoxidized dough needed in the production of high quality, yeast-leavenedproducts using ascorbic acid as the only oxidizing agent.

By achieving the objects in accordance with the purpose of theinvention, the present invention overcomes many disadvantages of thepotassium bromate replacers or other oxidizing agents that are currentlyin use. The advantages of the potassium bromate replacer provided in thepresent invention are:

(a) It comprises all natural ingredients.

(b) It is a slow acting oxidant that is functional throughout the entiremanufacturing process.

(c) It is an effective oxidant that produces properly oxidized doughneeded in the production of high quality, yeast-leavened products.

(d) It is specifically adapted for various methods of the breadmakingprocess.

Furthermore, the potassium bromate replacer provided in the presentinvention is a more effective oxidant than potassium bromate becausepotassium bromate has little effect on oxidation of dough during mixingand the early stages of proofing.

SUMMARY OF THE INVENTION

The present invention relates to potassium bromate replacer comprisingan ascorbic acid composition that replaces an oxidizing agent ofpotassium bromate. The potassium bromate replacer essentially comprisesascorbic acid, food acid, and/or phosphate.

In methods for preparing the ascorbic acid composition, it has beendiscovered that a food acid added in an effective amount slows downoxidation of ascorbic acid to dehydroascorbic acid in a dough and thus,ascorbic acid is changed to a slow acting oxidant that is functionalthroughout the entire manufacturing process. Now ascorbic acid and foodacid replace potassium bromate. It has also been found that a phosphateadded in an effective amount enhances complexing power of the food acid.This increase in an amount of copper-food acid complex formed during themixing stage of dough is particularly beneficial to continuously mixedand frozen doughs which require a high level of oxidant. Thus, ascorbicacid combined with a food acid and a phosphate is an effective oxidantthat produces properly oxidized dough needed in the production of highquality, yeast-leavened products using various methods of thebreadmaking process.

DETAILED DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS

The present invention relates to potassium bromate replacer thatcomprises an ascorbic acid composition. The present invention relatesfurther to the ascorbic acid composition suitable in the preparation ofpotassium bromate replacer and to methods for their preparation. Themethods for preparing the ascorbic acid composition and potassiumbromate replacer and the investigation results of how ascorbic acid isoxidized to dehydroascorbic acid in dough are described in detail below.

It is known to use all forms of ascorbic acid, organic acids, orphosphates (see, for example, U.S. Pat. No. 4,296,133, issued Oct. 20,1981 to Tanaka et al. entitled "Method for Producing Bread") asadditives to improve overall quality of breads or doughnuts. However,previous inventors or authors do not use ascorbic acid, food acid, orphosphate in dough as taught by the present invention. In the presentinvention, the ascorbic acid composition comprising ascorbic acid, foodacid, and phosphate is used as oxidizing agent replacers of potassiumbromate but not as additives. More specifically, ascorbic acid, foodacid, and phosphate are used to replace potassium bromate.

Throughout the specifications and claims, yeast-leavened products arethose prepared by forming a dough having flour, farinous material,yeast, and water. A manufacturing process for making yeast-leavenedproducts is defined as forming a dough by the steps or stages of mixing,proofing, and baking, or if the dough is frozen, the stages of mixing,freezing, thawing, proofing, and baking. A breadmaking process meansvarious methods such as Straight dough, Sponge dough, Liquid ferment, Notime dough, Frozen dough, and Continuously mixed dough. Percentages arebaker's formula percentages, that is, parts of weight per 100 partsflour. The wheat flour was milled from spring wheat and had 0.47% ashand 12.3% protein. No oxidizing agents were added in the flour mill.

Investigation of Ascorbic Acid Oxidation in Dough

To act as an oxidizing agent, ascorbic acid is first oxidized todehydroascorbic acid in dough. Although it is agreed that ascorbic acidis an effective oxidant during mixing and the early stages of proofing,scientists do not agree on exactly what makes it work. A general beliefis that enzymes present in flour oxidize ascorbic acid todehydroascorbic acid in dough in the presence of oxygen.

This oxidation reaction by molecular oxygen is accelerated by tracemetal ions such as copper or iron ion. Inhibiting the effect of metalions can be accomplished by adding a chelating agent to form complexesthat have little or no catalytic effects on the oxidation reactions.

Since metal ions such as copper and iron are present in flour as naturalbiological components, the mechanism for this metal-catalyzed oxidationof ascorbic acid in dough can be tested by adding chelating agents suchas sodium acid pyrophosphate or sodium hexametaphosphate to ayeast-leavened product mix formula. The bread mix formula for making adough are presented in Table 1.

                  TABLE 1    ______________________________________    Ingredient (in baker's %)                         Bread mix formula    ______________________________________    Flour                100.0    Compressed yeast     4.0    Sugar                6.0    Salt                 2.0    Oil                  3.0    Yeast food           0.5    Ascorbic acid        75       ppm    Water                62.0    ______________________________________

Adding 0.1 to 0.2 parts sodium acid pyrophosphate or sodiumhexametaphosphate per 100 parts flour to bread mix formula of Table 1produced soft, sticky, weak, and not easily machineable dough which aretypical characteristics of underoxidized dough, as compared to thecontrol dough which did not contain chelating agents.

Making metal ions inactive decreased oxidation of ascorbic acid todehydroascorbic acid in dough during the mixing stage, thereby producingunderoxidized dough. The results of this investigation illustrate thatascorbic acid in dough is oxidized to dehydroascorbic acid by ametal-catalyzed reaction. The copper (1.5 ppm) and iron (7.4 ppm)contents present in patent bread flour as intrinsic biologicalcomponents act as catalysts for oxidations of ascorbic acid in dough,occurring readily by aerobic oxidation as well as anaerobic oxidation.The fast complex formation with sodium acid pyrophosphate or sodiumhexametaphosphate and metal ions did not produce properly oxidized doughduring the mixing stage of dough, indicating that both of thesephosphates cannot be used to slow down oxidation rates of ascorbic acidin dough.

Food acids also have this chelation property. The food acids used asacidulants inactivate metal ions by forming the copper-food acid complexthat is dependent on the pH value of food products. Thus, the extent ofthis complex increases with increasing pH and the complex dissociatesinto the copper ion and the food acid with decreasing pH. For example,the dissociation constant of the cooper-malate complex at a pH of 3 to 4is reported as 3.89×10₋₅. At a pH between 6 and 8 copper ion exists onlyas the copper-malate complex. Thus, it is desirable to have a pH lowerthan 6 in the dough of yeast-leavened products.

Preparation of Ascorbic Acid Composition

The investigation results of ascorbic acid oxidation in dough illustratethat binding metal ions during the mixing stage of dough and freeingthese ions during the later stage of manufacturing process can slow downcatalytic effects of metal ions on the oxidation rates of ascorbic acidin dough throughout the entire manufacturing process. There are changesin the pH value of a dough by yeast fermentation or heat during themanufacturing process of yeast-leavened products. Thus, the pHdependency of metal ion-food acid complex has a role in the preparationof an ascorbic acid composition that slows down oxidation of ascorbicacid to dehydroascorbic acid in dough.

With some exception of sponge or liquid ferment, the pH value of freshlymixed dough is between 5.0 and 5.3. This means that a food acid added tothe bread mix formula given in Table 1 forms complexes with copper oriron ion present in flour during the mixing stage of dough, therebymaking these ions inactive. These complexes formed dissociate intocopper or iron ion and the food acid due to the gradual decrease in thepH value of dough by yeast fermentation during the later stages ofmanufacturing process, thereby freeing these ions and making these ionsagain act as catalysts for oxidation of ascorbic acid to dehydroascorbicacid in dough throughout the entire manufacturing process. Accordingly,a food acid slows down oxidation of ascorbic acid to dehydroascorbicacid in dough by forming metal ion-food acid complex during the mixingstage of dough and gradually dissociating into free metal ion and foodacid during the later stages of the manufacturing process. Thereby,ascorbic acid is changed from a fast acting oxidant to a slow actingoxidant. Thus, ascorbic acid combined with a food acid acts as a slowacting oxidant that is functional throughout the entire manufacturingprocess.

Ascorbic acid used in the present invention is L-ascorbic acid that actsas an oxidizing agent in dough. Ascorbic acid incorporated into ayeast-leavened product mix formula ranges from abut 10 ppm to 300 ppm,preferably about 15 ppm to 250 ppm by weight of flour.

Food acids are found in fruits, vegetables, their juices, and many otherfermented products. Some examples of food acids are acetic, citric,fumaric, lactic, malic, oxalic, phosphoric, succinic, tartaric, applejuice concentrate, orange juice concentrate, lemon juice concentrate,and wine. Citric acid, malic acid, apple juice concentrate, and orangejuice concentrate are preferred. Food acid ranging from about 0.015 to0.20 parts, preferably about 0.02 to 0.15 parts per 100 parts flour isadded to a yeast-leavened product mix formula.

In addition to emulsifying protein or strengthening gluten structure ofdough, the use of phosphate in the present invention has an additionalbenefit. The addition of phosphate increased the pH value of the doughto about 0.1 to 0.3 units. The complex formation with food acid andmetal ion increases with increasing pH. Thus, phosphate enhancescomplexing power of the food acid. The phosphate used are dibasic ortribasic phosphate such as dipotassium phosphate, disodium phosphate,trisodium phosphate, and tripotassium phosphate. Dibasic phosphate ispreferred. Phosphate ranging from about 0.1 to 0.5 parts, preferablyabout 0.15 to 0.40 parts per 100 parts flour is added to ayeast-leavened product mix formula.

Preparation of Potassium Bromate Replacer

The present invention relates further to the ascorbic acid compositionsuitable in the preparation of potassium bromate replacer and to methodsfor their preparation. The ascorbic acid composition provided in thepresent invention consists essentially of comprises ascorbic acid, foodacid, and phosphate.

As illustrated in the preparation of ascorbic acid composition, a foodacid added in an effective amount allows ascorbic acid to oxidize at aslow rate in a dough. Thus, ascorbic acid acts as a slow acting oxidantthat is functional throughout the entire manufacturing process. Nowascorbic acid and food acid replace an oxidizing agent of potassiumbromate.

The phosphate enhances complexing power of food acid by increasing thepH value of a dough. This increase in an amount of metal ion-food acidcomplex formed during the mixing stage of dough enables the baker to usea high level of oxidant without fear of producing overoxidized dough.Thus, the use of phosphate is particularly beneficial to continuouslymixed and frozen doughs which require a high level of oxidant.Accordingly, ascorbic acid combined with a food acid and a phosphate isan effective potassium bromate replacer that produces properly oxidizeddough needed in the production of high quality, yeast-leavened productsusing various methods of the breadmaking process.

Commercial Application

Yeast-leavened products could not be made as economically as they are ifsuitable oxidizing agents were not available to the baker. Withoutproper oxidation of dough, costly, high protein flour may be needed andabsorption may have to be lowered. Dough made without an oxidizing agenttends to be more sticky and more difficult to handle, leading to lowerproduction rates.

The present invention is uniquely useful for manufacturingyeast-leavened products without using chemical oxidizing agents oradditives at the levels specified by the FDA, permitting the baker toproduce high quality products using only natural ingredients. Thus,consumers buy natural baked goods at lowest reasonable cost.

Using the preceding description, the baker can utilize the presentinvention to produce high quality, yeast-leavened products withoutfurther elaboration. The following preferred embodiments are presentedas merely illustrative, but is not specifically limited to the exampledescribed below.

EXAMPLE 1

    ______________________________________                                     Potassium                                     Bromate    Ingredient    Bread Mix          Replacer    (in baker's 4)                  Formula   Control  I     II    ______________________________________    Flour         100.0    Compressed yeast                  4.0    Sugar         6.0    Salt          2.0    Oil           3.0    Yeast food    0.5    Water         62.0    Ascorbic acid           75 ppm   75 ppm                                           100    Citric or Malic acid             0.08  0.1    Dipotassium phosphate                  0.2    ______________________________________

As shown in Example I, Potassium bromate replacer I comprises ascorbicacid and food acid. Potassium bromate replacer II comprises ascorbicacid, food acid, and phosphate. Conventional dough process such asstraight dough or sponge dough requires a low level of oxidant and thus,potassium bromate replacer I is recommended. However, continuously mixedand frozen doughs require a high level of oxidant and thus, potassiumbromate replacer II is recommended.

The control dough was prepared by adding ascorbic acid to the bread mixformula listed in Example I. The effectiveness of potassium bromatereplacer I or II was tested by adding these replacers to the bread mixformula listed in Example 1. Bread was made according to the No timedough process at a commercial bakery. The dough was mixed for 15minutes, rested for 20 minutes, then divided and placed through theusual No time dough processing steps.

The investigation conducted with various food acids found differences inthe reaction rate of complexes formed in dough during a 15 minute mixingstage. One example of food acids is 80% phosphoric acid. The addition ofphosphoric acid to the control dough formed the copper-phosphoratecomplex at a fast rate during a 15 minute mixing stage, making the doughunsuitable by producing underoxidized dough and unsatisfactory bread.Another example of food acids is 20% liquid vinegar (acetic acid). Therewas enough copper-acetate complex formed during a 15 minute mixingstage. Proofing to a standard height produced excellent oven spring.Bread volume was good to excellent but had slightly coarse grain. Aceticacids formed by yeast fermentation seem to accelerate the dissociationof the copper-acetate complex during proofing, resulting in slightlycoarse grain. The control containing 0.2 to 0.3 parts apple juiceconcentrate (70%) per 100 parts flour produced quality bread having goodvolume, fine grain and texture, and pleasant aroma.

Accordingly, if the effective amount of a food acid such as citric acid,malic acid, fruit juice concentrate or wine is used in combination withascorbic acid in dough, the oxidation of ascorbic acid todehydroascorbic acid in dough is slowed down and the properly oxidizeddough is produced throughout the entire manufacturing process ofyeast-leavened products. The dough proofed to a standard height showedgood oven spring and the bread was of high quality in volume, symmetry,grain and texture. However, the use of food acid which forms complexesat a fast rate produced underoxidized dough and unsatisfactory bread,The use of food acid which forms complexes at a low rate producesoveroxidized dough and also produced unsatisfactory bread. Underoxidizeddough is not easily machineable but if the dough is overproofed, thebread had a satisfactory volume but poor symmetry.

The investigation results illustrate that oxidation of ascorbic acid todehydroascrobic acid in dough occurs readily by aerobic oxidation aswell as anaerobic oxidation. Even in the presence of air, oxidation ofascorbic acid proceeds largely by a nonenzymatic mechanism. Traces ofcopper not only catalyze aerobic oxidation of ascorbic acid but alsoinitiate reactions leading to a secondary oxidation of ascorbic acidunder anaerobic conditions.

About 20% of flour bulk is made up of air. The iron salts have anaccelerating effect on copper-catalyzed oxidation of ascorbic acid,although iron alone has little effect. The iron content of flour can beincreased by enriching flour with Ferrous Sulfate. Thus, even in anenclosed chamber of continuous mixing systems, the combined use ofascorbic acid, food acid, phosphate, and ferrous sulfate as anenrichment in continuously mixed dough allows bakers to produce properlyoxidized dough for production of quality bread.

Frozen dough requires a high level of oxidant. Frozen dough containingascorbic acid, food acid, and phosphate produced good oven spring andquality bread.

Summarizing, it has been discovered that a food acid added in aneffective amount slows down oxidation of ascorbic acid todehydroascorbic acid in a dough, thereby ascorbic acid is changed to aslow acting oxidant and a phosphate increases the amount of complexformation with food acid and metal ion. Thus, the ascorbic acidcomposition essentially comprises ascorbic acid, food acid, andphosphate and replaces an oxidizing agent of potassium bromate or otheroxidizing agents. The potassium bromate replacer provided in the presentinvention is a more effective oxidant that potassium bromate becausepotassium bromate has little effect on oxidation of dough during mixingand the early stages of proofing. Ascorbic acid, food acid, andphosphate are considered to be generally recognized as safe (GRAS).Thus, there are no limits on usage levels. Utilizing the presentinvention, bakers can now produce natural baked goods of high quality atthe lowest reasonable cost to meet the consumer's demand.

Many modifications and variation of the present invention are possiblein light of the above teachings. Variations may be made in proportions,procedures, and materials without departing from the scope of thisinvention which is defined the appended claims.

What is claimed is:
 1. A potassium bromate replacer compositioncomprising an ascorbic acid composition in an effective amount toreplace an oxidizing agent of potassium bromate, said ascorbic acidcomposition consisting essentially of comprising:(a) about 15 to 250 ppmascorbic acid by weight of flour, (b) about 0.02 to 0.15 parts food acidper 100 parts flour, and (c) about 0.15 to 0.40 parts phosphate per 100parts flour.
 2. The composition of claim 1, wherein said food acid isselected from the group consisting of acetic acid, citric acid, fumaricacid, lactic acid, malic acid, oxalic acid, tartaric acid, apple juiceconcentrate, orange juice concentrate, and mixtures thereof.
 3. Thecomposition of claim 1, wherein said phosphate is selected from thegroup consisting of dipotassium phosphate, disodium phosphate, trisodiumphosphate, tripotassium phosphate, and mixtures thereof.